Integrated circuits find application in many of today's consumer electronics, such as cell phones, video cameras, portable music players, printers, computers, etc. Integrated circuits may include a combination of active devices, passive devices and their interconnections.
Flip chip packaging is an advanced integrated packaging design that meets the demand for faster integrated circuit technology with increased input/output (I/O) leads. Flip chip packaging is a technique of mounting the active side of a chip with the surface bonding pads toward the substrate. This packaging technique is currently the design with the shortest path from the chip to the substrate, thereby providing a good electrical connection for high speed signals.
Capillary underfill techniques are becoming very important for new product development within the flip chip device market. Typically, flip chip devices and/or packages utilizing capillary underfill material have encountered various defects, such as bleeding on the printed circuit board surface (due to the low viscosity of the capillary underfill material) and/or delamination problems between the underfill and the solder resist material. Commonly, these delamination problems occur because of moisture absorption at the capillary underfill fillet area between the flip chip device and the printed circuit board due to low fillet strength. It is known that the fillet area of a flip chip device experiences more stress than the center of the device or package.
Thus, a need still remains for a reliable integrated circuit packaging system and method of fabrication, wherein the integrated circuit packaging system exhibits reduced resin or underfill bleeding, reduced delamination problems, reduced moisture absorption, and increased fillet strength. In view of the ever-increasing commercial competitive pressures, along with growing consumer expectations and the diminishing opportunities for meaningful product differentiation in the marketplace, it is critical that answers be found for these problems. Additionally, the need to reduce costs, improve efficiencies and performance, and meet competitive pressures adds an even greater urgency to the critical necessity for finding answers to these problems.
Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art.